Patients with cannabis use disorder who underwent heart surgery had similar in-hospital outcomes to matched controls — but they were far more likely to also use tobacco, opioids, cocaine, and alcohol.
Cardiac surgery patients who use cannabis, cardiothoracic surgeons, anesthesiologists assessing preoperative risk, addiction medicine specialists.
What the researchers found
Analyzing 846,837 cardiovascular surgery patients from a national database, researchers identified 11,724 (1.4%) with a cannabis use disorder diagnosis. After carefully matching these patients to controls with similar baseline characteristics and comorbidities, cannabis use disorder was not associated with additional in-hospital complications or death.
However, the data revealed something else: patients with cannabis use disorder had dramatically higher rates of polysubstance use. They were significantly more likely to also smoke tobacco, abuse opioids, use cocaine or stimulants, and abuse alcohol compared to matched controls. These co-occurring substance use patterns were the dominant clinical feature of the CUD population.
Specific complications like pneumonia (13% vs. 9.4%) were higher in the CUD group, but the researchers attributed these differences to the polysubstance use profile rather than cannabis itself.
Why it matters
For the growing number of patients who use cannabis and need cardiac surgery, this study provides reassurance that cannabis use disorder alone doesn't appear to worsen surgical outcomes. But it also highlights that CUD rarely exists in isolation — the polysubstance use patterns that accompany it are what clinicians should be screening for and managing in the surgical setting.
The numbers in context
846,837 total cardiovascular surgery patients. 11,724 (1.4%) with CUD. Pneumonia: 13% CUD vs. 9.4% controls. Significantly higher rates of co-occurring tobacco, opioid, cocaine/stimulant, and alcohol use in CUD patients. No significant difference in in-hospital mortality after matching.
How the study worked
Retrospective observational study using the Nationwide Readmissions Database (2016–2018). Identified 846,837 cardiovascular surgery patients, 11,724 with CUD diagnosis. Used 1:1 balancing-score matching to control for baseline characteristics and comorbidities when comparing outcomes.
Who was studied
N=846,837 patients undergoing cardiovascular surgery, including 11,724 with cannabis use disorder, US national database from 2016-2018.
What this study cannot tell us
Retrospective database study relying on ICD codes for CUD diagnosis — likely underestimates true cannabis use since many users don't receive a formal CUD diagnosis. Cannot distinguish between active use and historical use at the time of surgery. The 2016–2018 data predates recent increases in cannabis potency and use. In-hospital outcomes only — doesn't capture post-discharge complications.
How to read the evidence
Large observational study with careful matching from a national database — provides good real-world evidence but cannot fully control for all confounders, particularly unmeasured polysubstance effects.
When this study was published
Published in 2026 using 2016–2018 data. Cannabis use patterns and potency have shifted since the data collection period.
The bigger picture
This adds to the cardiovascular cannabis evidence (connecting to RTHC-00167 on adolescent cardiac complications and RTHC-00178 on cannabis and cardiovascular health) by examining surgical outcomes specifically. The finding that CUD is a marker for polysubstance use rather than an independent surgical risk factor is clinically actionable — it suggests the clinical conversation should focus on the full substance use picture rather than cannabis in isolation.
Replication
Not stated in abstract.
Funding
Not reported in abstract.
Conflicts of interest
Not reported in abstract.
Questions still open
- Would active THC use at the time of surgery (vs. a historical CUD diagnosis) produce different outcomes? Does the method of cannabis consumption (smoking vs. edibles) affect perioperative risk? How should cardiac surgery teams incorporate cannabis use screening into preoperative assessment?
Read the original research
Nationwide outcomes of cardiac surgery in patients with cannabis use disorder.
Journal of cardiothoracic surgery, 21(1)
The Journal of Cardiothoracic Surgery is a peer-reviewed journal focusing on research in the field of cardiothoracic surgery.
Citation
Dewan, Krish C; Mahboubi, Rashed; Xu, Samantha; Maigrot, Jean-Luc A; An, Crystal; Zhou, Guangjin; Ferre, Jose L Diz; Koroukian, Siran M; Weiss, Aaron J; Soltesz, Edward G. (2026). Nationwide outcomes of cardiac surgery in patients with cannabis use disorder.. Journal of cardiothoracic surgery, 21(1). https://doi.org/10.1186/s13019-025-03755-6
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